Deep fryer

ABSTRACT

The invention relates to a deep-fat fryer having a frying vessel ( 17 ) and at least one heating element ( 26 ) arranged in the frying vessel ( 17 ). The frying vessel accommodates a frying medium, for example frying fat or oil, the heating element first of all melting the latter, if appropriate, and then heating it to a temperature of from typically 100 to 200° C., in particular of from 150 to 190° C. In the case of known deep-fat fryers, the frying vessel usually consists of metal, for example stainless steel, enameled steel or coated, non-coated or anodized aluminum. In contrast, the deep-fat fryer according to the invention is characterized in that the frying vessel ( 17 ) consists, at least in part, of a transparent or see-through material, which allows visual monitoring of the frying process.

The invention relates to a deep-fat fryer having a frying vessel and atleast one heating element arranged in the frying vessel.

Such deep-fat fryers are known. The frying vessel accommodates a fryingmedium, for example frying fat or oil, the heating element first of allmelting the latter, if appropriate, and then heating it to a temperatureof from typically 100 to 200° C., in particular of from 150 to 190° C. Awide range of different foodstuffs, referred to here as items forfrying, such as meat, fish, onion rings, mushrooms, vegetables, chipsand the like can be fried within a period of a few minutes in the heatedfat or oil. The term “frying” in the present context covers any methodof treating foodstuffs in hot fat or oil. Use is usually made, for thepurpose of frying, of a basket which accommodates the items for fryingand may consist, for example, of a wire mesh. The basket ensures thatthe items for frying can be reliably and easily submerged in the hot oilor fat and removed again following completion of the frying process. Theexcess fat or oil can drip off through the wire mesh.

Numerous deep-fat fryers, for example the deep-fat fryer described bythe applicant in German patent application DE 197 14 038 A, has aheating element which is firmly connected to the frying vessel. Theheating element is then usually fastened beneath the frying vessel, withthe result that first of all the frying vessel, and then the oil or fatlocated in the frying vessel, is heated. In this case, the fryingvessels have to have good thermal conductivity and thus usually consistof metal. In order to protect the user, in the case of such appliances,the frying vessel is usually enclosed by an insulating housing in orderto avoid the risk of the user accidentally coming into contact with thehot frying vessel.

Frying vessels in the case of which the heating element is arranged inthe interior of the frying vessel are also known. Advantages of thistype of appliance are that the heating element is in direct contact withthe fat or oil, this ensuring that the frying medium heats up morequickly. The heating element is typically designed as a heating coil,with the result that smaller residues of the items for frying can passthe heating element and sink to the base of the frying vessel. Suchparticles and food residues are then located in the cooler base regionof the frying vessel rather than in the immediate vicinity of theheating element. During the subsequent frying processes, such residuesthus burn and disintegrate to a considerably lesser extent than is thecase, for example, for frying vessels with base heating. The frying fator oil can then be used for a longer period of time because it does notcontain as many disintegrated food residues. Even in the case of thedeep-fat fryer with the heating element arranged in the frying vessel,though, the frying vessel itself usually consists of metal, for examplestainless steel, enameled steel or coated, non-coated or anodizedaluminum.

When using the known deep-fat fryers, the user cannot tell eitherwhether the frying fat has already melted, and the heating output canthus be increased, or whether the item for frying has already reachedthe desired degree of browning and the frying process can thus becompleted. The user is thus frequently forced to open the lid of thedeep-fat fryer in order to monitor the frying process. It is usuallyeven necessary to remove the frying basket in order to monitor visuallythe items for frying. This is not just laborious and time-consuming, butalso involves the risk of the correct time for completing the fryingprocess passing and the items for frying consequently burning. Inaddition, frequent handling of foodstuffs having a high moisture contentinvolves the risk of burning by splashes of fat.

The object of the present invention is thus to provide a deep-fat fryerwhich allows straightforward monitoring of the frying process. Theintention here is to ensure that the user is sufficiently protectedagainst splashes of fat, and also against accidental contact with thehot frying vessel.

This object is achieved by the deep-fat fryer having the features of thepresent claim 1. Advantageous developments of the deep-fat fryeraccording to the invention form the subject matter of the dependentclaims.

Accordingly, the present invention relates to a deep-fat fryer having afrying vessel and at least one heating element arranged in the fryingvessel, characterized in that the frying vessel consists, at least inpart, of a transparent or translucent material. The use of an at leastpartially transparent or translucent frying vessel makes it possible forthe user to follow the frying process directly and to monitor the degreeof browning of the items for frying which are floating in the hot oil orfat. Intervention on the part of the user is only necessary at the endof the frying process, with the result that the risk of injury isreduced to a considerable extent and the risk of burning the items forfrying is vastly reduced. Since, in the case of all the commerciallyavailable deep-fat fryers known to the applicant, the frying vesselconsists of opaque metal and visual monitoring of the items for fryingin the hot oil is not possible, it was surprising to realize, by thesolution according to the invention, a deep-fat fryer which allows suchmonitoring and, at the same time, maintains the functionality andoperational reliability of conventional deep-fat fryers.

According to a preferred embodiment of the invention, the frying vesselconsists entirely of a transparent or translucent material, with theresult that optimum visual monitoring of the frying process through thelateral circumference of the frying vessel is ensured. Turbulence andbubbling surfaces of the frying medium, which prevent visual monitoringfrom above in the case of conventional deep-fat fryers, do not obstructthe monitoring process in the case of the deep-fat fryer according tothe invention. The frying vessel preferably consists of glass, forexample a heat-resistant safety glass, a temperature-resistanttransparent plastic material or else a translucent metal or a metalalloy. It is also possible for the frying vessel to consist of acombination of these materials, although frying vessel made of glass orplastic are preferred. The frying vessel may or may not be colored, forexample dyed or painted, as long as optimum monitoring of the items forfrying is not significantly impaired. The term “temperature-resistant”in the present context means that, up to typical frying temperatures ofapproximately 200° C., the transparent plastic is essentiallydimensionally stable, does not soften and also does not disintegrate.The heating element is advantageously arranged in the region of the baseof the frying appliance. It is particularly preferable for the heatingelement to be removable, with the result that the transparent fryingvessel can easily be cleaned. The heating element may be arranged, forexample, in the form of a heating coil. The heating element isadvantageously connected to a holder which can be fitted, or fastened insome other way, for example on the outside of the frying vessel. Athermostat for controlling the heating output of the heating element isadvantageously arranged in the holder. For this purpose, it is possibleto provide, for example, one or more temperature sensors, which arearranged in the vicinity of the heating element, advantageously directlyon the heating element, and are in thermal contact therewith. Suitableoperating elements which allow the heating element to be switched on andoff may be arranged on the holder. The heating element is usuallyoperated electrically, with the result that the operating elementsactivate the electrical contact with a power cable opening out into theholder. Since an optimum frying result requires different fryingtemperatures for different foodstuffs, the frying temperature canpreferably be adjusted by the user. For this purpose, the deep-fat fryermay have, on the holder for the heating element, a temperaturecontroller which can be adjusted by the user and, in turn, controls thethermostat. It is usually the case that frying fat, with a very lowheating output, is first of all melted and then the liquid fat, or aliquid oil which is already at room temperature, is heated up to theactual frying temperature, which is usually between 100 and 200° C. Thethermostat usually also comprises suitable fuses which interrupt thepower supply if a predetermined temperature limit value, for example210° C., is exceeded.

If the frying oil being worked with is at a temperature of almost 200°C., there is a considerable risk of injury to the user if he/sheunintentionally comes into contact with the frying vessel. The outershell of the deep-fat fryer, which is accessible to the user, shouldthus always be at a considerably lower temperature than the fryingmedium. In the case of the deep-fat fryer according to the invention,the frying vessel preferably consists of glass or a transparent plastic,i.e. of materials which have a usually a relatively low thermalconductivity. The frying vessel may thus be designed, for example, in adouble-walled manner with an evacuated interspace, with the result thatthe temperature level of the outer wall is considerably lower than thetemperature of the frying medium. It is particularly preferable,however, for the frying vessel to be arranged in a housing, whichprevents the user from coming into direct contact with the hot fryingvessel. In order to maintain the advantage of visual monitoring of thefrying process, the housing likewise has to be at least partiallytransparent or see-through. It is thus possible for the housing toconsist, at least in part, of a see-through plastic material. Thehousing, however, may also have, for example, metal or plastic struts,between which there are open interspaces, through which the user can seeinto the interior of the frying vessel. The dimensions of, and spacingsbetween, the struts here are selected such that, on the one hand,unobstructed visual monitoring is ensured and, on the other hand, theuser's hands are prevented from accidentally coming into contact withthe frying vessel. The struts may be designed, for example, ashorizontally running rings or ring segments. The frying vessel isadvantageously arranged in the housing such that the thermal contactbetween the frying vessel and housing is minimized. There are thuspreferably only a few points of contact between the frying vessel andhousing, at which it is possible to arrange, for example, silicone orTeflon plates or the like, which further reduce the coefficient of heattransfer between the frying vessel and housing and form a softer bearingmeans than, for example, the metal struts themselves. It is particularlypreferred for the frying vessel to be arranged in a removable manner inthe housing, which further simplifies the task of cleaning the deep-fatfryer according to the invention.

For the safety considerations mentioned above, it is possible for thedeep-fat fryer according to the invention to be additionally enclosed onthe outside, at least in part, by a protective casing. The protectivecasing, in the event of the frying vessel being damaged, preventsfragments of the vessel or hot fat from being able to shoot outlaterally and harm the user.

The protective casing preferably consists of a transparent ortranslucent material, for example of plastic, glass or a combination ofthese materials, a protective casing made of plastic being particularlypreferred. The protective casing, likewise, may or may not be colored.The protective casing is always configured such that the view of theitems for frying floating in the see-through or translucent fryingvessel is not impaired.

The protective casing preferably encloses the frying vessel in thelateral region and is designed such that, in the case of the fryingvessel being damaged, the oil is channeled downward in a controlledmanner into the base region of the deep-fat fryer. For this purpose, theprotective casing may have a closed base region and thus enclose thefrying vessel in a hemispherical manner. It is preferable, however, forthe base region of the protective casing to be open, with the resultthat the oil can flow into the base region of the deep-fat fryer. Thebase region of the deep-fat fryer may likewise be closed or, preferably,provided with possibly closeable outlet openings, via which the oil canflow out. The base region of the deep-fat fryer is preferably alwaysdesigned such that, once the frying vessel has been damaged, the maximumoil level drops beneath the heating device and the electrical controls,with the result that the deep-fat fryer is electrically safe even in theevent of malfunctioning.

If outlet openings are arranged in the base region of the deep-fat fryeror in the base region of the protective casing, filter means, forexample small-diameter openings, screens, lattices or grilles or alsoporous filter materials, will preferably be provided, these controllingthe outflow of the oil in the downward direction from the deep-fat fryerand retaining, in particular, fragments of the frying vessel, with theresult that it is possible to avoid the user being put at risk, forexample, by splinters of glass. The oil preferably flows out slowlyenough for it to be able to cool to a great extent and thus for any riskor injury by hot oil to be eliminated. The filter means may consist ofporous glass materials, for example a silicate aerogel, a plasticmaterial, metal or a woven fabric.

Fastening means are preferably provided for fixing the protective casingin the deep-fat fryer. The fastening means are advantageously designedas securing means which fix the protective casing on the housing of thedeep-fat fryer. The protective casing may be fastened in a permanent orreleasable manner on the housing. In particular in the latter case, theprotective casing is preferably of washable, for exampledishwasher-safe, design.

An air gap is advantageously defined between the frying vessel and theprotective casing, said air gap ensuring effective thermal separationbetween the protective casing and the frying vessel, which is hot whenin operation, with the result that the protective casing, which ispossibly accessible from the outside, can be kept at a considerablylower temperature. A few spacers with low thermal conductivity may bearranged between the frying vessel and the protective casing. It isparticularly preferable for the fastening means for the protectivecasing to serve, at the same time, as spacers for the frying vessel. Thefastening means may be designed, for example, such that they retain thefrying vessel on their inside and/or at their top border or their topedge.

The deep-fat fryer according to the invention preferably also comprisesa removable basket for the items for frying. It is likewise advantageousto provide a removable lid, which may have, for example, suitablesealing lips which rest on the border of the frying vessel.

The frying vessel of the deep-fat fryer according to the invention maybe in a wide range of different shapes, for example it may be ofhemispherical, cuboidal or cylindrical design.

The invention is explained in more detail hereinbelow with reference toexemplary embodiments illustrated in the attached drawings.

In the drawings:

FIG. 1 shows an end view of a first embodiment of the deep-fat fryeraccording to the invention;

FIG. 2 shows a side view of the deep-fat fryer of FIG. 1;

FIG. 3 shows a cross section of the deep-fat fryer of FIG. 1;

FIGS. 4–7 show variants of the transparent or translucent frying vesselsof the deep-fat fryer according to the invention;

FIG. 8 shows an end view of a second embodiment of the deep-fat fryeraccording to the invention, partly in section;

FIG. 9 shows a side view of the deep-fat fryer of FIG. 8, partly insection;

FIG. 10 shows a detail of a variant of the deep-fat fryer of FIGS. 8 and9, partly in section;

FIG. 11 shows a detail of the further variant of the deep-fat fryer ofFIGS. 8 and 9, in cross section;

FIG. 12 shows a detail of yet a further variant of the deep-fat fryer ofFIGS. 8 and 9, in cross section; and

FIG. 13 shows a further variant of the deep-fat fryer of FIGS. 8 and 9,in cross section.

FIG. 1 shows an end view of a preferred embodiment of the deep-fat fryer10 according to the invention. The deep-fat fryer 10 has a housing 11which comprises a base plate 12 from which vertical carriers 13 extendupward. One of the vertical carriers is designed as a rail 14 for aholder 15 of a heating element (not illustrated in FIGS. 1 and 2). Therail 14 is clearly visible, in particular, in the side view of FIG. 2.Securing struts 16 are formed between the carriers 13, 14. A transparentfrying vessel 17 is arranged in the pot-like housing 11 formed by thebase plate 12, the vertical carriers 13, 14 and the horizontal securingstruts 16. There is a free space 18 between the horizontal securingstruts 16, and this free space makes it possible for the user to monitorvisually the items for frying (not illustrated in the figures) floatingin hot oil in the frying vessel 17. A removable lid 19, which has ahandle 20, is arranged on the deep-fat fryer 10. An on/off switch,designed as a toggle switch 21, and a temperature controller 22 foradjusting the desired frying temperature are arranged on the holder 15.The temperature controller 22 interacts with a thermostat arranged inthe interior of the holder 15. An operating light 23 indicates whetherthe deep-fat fryer 10 is switched on. The illustration of FIGS. 1 and 2also shows a handle 24 belonging to a frying basket which, for the sakeof clarity, is not illustrated specifically. In the storage stateillustrated in FIGS. 1 and 2, the handle 24 has been swung back in aspace-saving manner and, for use purposes, can be swung out in thedirection of the arrow illustrated in FIG. 2 and anchored in a recess 25of the holder 15. In order to remove the frying basket, the struts 24 aand 24 b can easily be pressed together and released from the anchoringin the recess 25 of the holder 15.

FIG. 2 shows a side view of the deep-fat fryer 10 of FIG. 1, the samecomponents being provided with the same designations.

FIG. 3 shows the deep-fat fryer in the same orientation as in FIG. 2,but in cross section. It is possible to see the transparent fryingvessel 17, in which a heating element 26, which is connected to theholder 15, is arranged in a removable manner. When the heating element26 is inserted into the frying vessel 17, the holder 15 is positioned onthe rail 14 and strikes against the base plate 12. This ensures both aconstant orientation of the heating element 26 and a constant spacingbetween the heating element and the base region 27 of the frying vessel17. The thermostat 28 and a safety thermostat, which can be resetmanually via a push-button 29, are arranged in the holder 15. Thethermostats are connected to temperature sensors (not illustrated) whichare mounted in the region of the heating coil of the heating element 26.The cross-sectional illustration of FIG. 3 shows that the frying vessel17 is only in contact with the housing 11 at a few points 30. The pointsof contact 30 may be designed as Teflon or silicone plates, whichfurther reduce the thermal contact.

FIGS. 4–7 illustrate a wide range of different embodiments 17′, 17″,17″″, 17″″ of the frying vessel 17.

FIG. 8 illustrates an end view of a second embodiment of the deep-fatfryer according to the invention, partly in section. Componentscorresponding to components which have already been explained above withreference to the deep-fat fryer 10 of FIGS. 1 to 3, or which fulfill acorresponding function, are provided with the same designations and areonly described briefly, if at all, hereinbelow. The deep-fat fryer 10 ofFIG. 8 corresponds for the most part to the deep-fat fryer of FIGS. 1 to3, although the removable frying basket 32 is also shown, in addition,partly in section. As a significant contrast to the deep-fat fryer ofFIGS. 1 to 3, the deep-fat fryer of FIG. 8 has a protective casing 33made of a transparent plastic material, for example of Plexiglas, whichencloses the frying vessel 17 on the outside. Should the frying vessel10 be broken, for example, by incorrect use, the protective casing 33effectively prevents fragments of glass from being able to shootlaterally outward, or hot oil 34 from being able to splash laterallyoutward, through the open interspaces 18 between the annular metalstruts 16. An air gap 35 is formed between the frying vessel 17 and theprotective casing 33 and gives rise to thermal separation between thefrying vessel and protective casing, with the result that, even when thedeep-fat fryer is in operation, the protective casing 33 is only heatedto a moderate extent. The protective casing 33 is open in its bottomregion 36, and the oil 34 which escapes in the event of damage canthereby be channeled into the bottom region 37 of the deep-fat fryer 10.

FIG. 9 shows a side view of the deep-fat fryer of FIG. 8, partly insection. It can be seen, in particular, that small-diameter openings 38are provided in the bottom region 37 of the deep-fat fryer, saidopenings, on the one hand, allowing the oil to escape slowly and in acontrolled manner and, on the other hand, acting as filter means whichretain fragments of the frying vessel 17. Also provided is a holder 39which serves as fastening means for fixing the protective casing 33 andhas protruding pins 40 which engages, through corresponding bores in theprotective casing 33, in depressions which are made in the carriers 13.It is possible for the pins 40 to be retained by a press fit or to beadhesively bonded on a permanent basis in the depressions. In the formercase, it is also possible for the protective casing 33 to be fastened ina releasable manner. As can be seen, the holder 39 serves, at the sametime, as a spacer for the frying vessel 17, in order thus to ensure theair gap 35. In the variant of FIGS. 8 and 9, the inner contour of theholder 39 is adapted essentially to the inner contour of the fryingvessel 17, with the result that the vessel 17 rests on the inside of theholder 39.

In contrast, in the case of the variant illustrated in FIG. 10, thefrying vessel 17 is borne by the top edge 41 of the holder 39, with theresult that a certain air gap 35 is also present in the region of theholder.

FIG. 11 illustrates a variant of the base region of the deep-fat fryerof FIGS. 8 and 9, in cross section, in the case of which the filtermeans of the outlet openings are designed as a grille-like screen orlattice 42. As can be seen, in the illustration of FIG. 11, the fryingvessel 17 has been broken, but the filter means effectively retain thefragments of glass 43, while the oil 34, as is illustrated by thearrows, can flow out downward.

FIG. 12 shows a further variant of the deep-fat fryer according to theinvention in an illustration corresponding to FIG. 11. In the case ofthis variant, the filter means are designed as a porous filter material44.

In the case of that embodiment of the deep-fat fryer according to theinvention which is illustrated, finally, in FIG. 13, the base region 37of the deep-fat fryer is closed, with the result that, in the event ofmalfunctioning which is illustrated, the frying vessel 17 havingshattered into numerous fragments 43, the oil 34 cannot flow out of thehousing. Nevertheless, the oil is distributed in the base region 37 ofthe deep-fat fryer such that since maximum oil level is a considerableway below the level of the heating coil 26 of the deep-fat fryer.

1. Deep fat fryer comprising a vessel and at least one heating elementarranged in said vessel, said vessel being made entirely from atransparent or translucent material, and a protective guard made from atransparent or translucent material being provided at least partiallycircumferentially around said vessel.
 2. Deep fat fryer according toclaim 1, wherein said protective guard is made from one or more of thegroup consisting of plastic and glass.
 3. Deep fat fryer according toclaim 2, wherein the protective guard is colored.
 4. Deep fat fryeraccording to claim 1, wherein the protective guard is provided with aclosed bottom.
 5. Deep fat fryer according to claim 1, wherein adischarge aperture is provided in the bottom part of said protectiveguard.
 6. Deep fat fryer according to claim 5, including a filter insaid discharge aperture of said bottom part.
 7. Deep fat fryer accordingto claim 1, including a fixing device adapted to maintain saidprotective guard in said fryer.
 8. Deep fat fryer according to claim 1,wherein an air gap is provided between said vessel and said protectiveguard.
 9. Deep fat fryer according to claim 7, wherein said fixingdevice comprises spacers for said vessel.
 10. Deep fat fryer accordingto claim 7, wherein said protective guard is removably arranged in saidfryer.
 11. Deep fat fryer according to claim 1, wherein the transparentor translucent material is made of one or more of the group consistingof glass, a temperature resistant plastics, and metal.
 12. Deep fatfryer according to claim 1, wherein the vessel is colored.
 13. Deep fatfryer according to claim 1, wherein the heating element is removablyarranged near the bottom of the vessel.
 14. Deep fat fryer according toclaim 13, wherein the heating element is connected to a mount whichcomprises a thermostat for controlling the heating output of saidheating element.
 15. Deep fat fryer according to claim 1, including atleast partially transparent housing which accommodates said vessel. 16.Deep fat fryer according to claim 15, wherein the housing is at leastpartially made from a transparent plastics.
 17. Deep fat fryer accordingto claim 15, wherein the housing comprises metallic and/or plasticstruts with a clear spacing being provided between said struts.
 18. Deepfat fryer according to claim 15, wherein said vessel is removablyarranged in said housing.
 19. Deep fat fryer according to claim 1,wherein said fryer comprises a removable basket which accommodates goodsto be fried.
 20. Deep fat fryer according to claim 1, wherein saidvessel is provided with a removable lid.